adj. clean·er, clean·est
1. Free from dirt, stain, or impurities; unsoiled: a clean kitchen floor; clean clothes.
a. Free from foreign matter or pollution; unadulterated: clean air; clean drinking water.
b. Not infected: a clean wound.
a. Producing relatively little pollution: a clean fuel; a cleaner, more efficient engine.
b. Producing relatively little radioactive fallout or contamination: a clean nuclear bomb.
4. Having no imperfections or blemishes; regular or even: a clean edge; a smooth, clean joint.
a. Not ornate or intricate; spare: "the clean lines and exquisite proportions of early modernism" (Judith Thurman).
b. Sharply defined; clear-cut: a clean outline against the sky.
6. Free from clumsiness; deft; adroit: a clean throw.
7. Devoid of restrictions or encumbrances: a clean bill of health.
8. Thorough; complete: a clean getaway.
9. Having few alterations or corrections; legible: clean manuscript.
10. Blank: a clean page.
a. Morally pure; virtuous: led a clean life.
b. Having no marks of discredit or offense: a clean voting record.
12. Fit for all readers, listeners, or audiences; not ribald or obscene: a clean joke.
13. Honest or fair: a clean fighter; a clean competition.
a. Not carrying concealed weapons or drugs.
b. Innocent of a suspected crime.
a. Free from narcotics addiction.
b. Showing no evidence of using banned or performance-enhancing substances: proven to be clean before the race.
adv. cleaner, cleanest
1. So as to be unsoiled: wash the dishes clean.
2. In a fair manner: played the game clean.
3. In a clean or nonpolluting manner: a fuel that burns clean.
4. Informal Entirely; wholly: clean forgot the appointment.
v. cleaned, clean·ing, cleans
1. To rid of dirt, rubbish, or impurities: clean a room; clean a suit.
2. To get rid of (impurities or dirt, for example); remove: cleaned up the trash; cleaned off the stains.
3. To prepare (fowl or other food) for cooking, as by removing the entrails or fat.
4. To remove the contents from; empty: cleaned my plate.
5. Sports To lift (a barbell) from the floor to the shoulders in one motion.
To undergo or perform an act of cleaning.
1. To rid of dirt, rubbish, or impurities.
2. To empty of contents or occupants.
3. Informal To drive or force out: cleaned out the incompetent workers.
4. Slang To deprive completely of money or material wealth: The robbery cleaned us out.
1. To make clean or orderly.
2. To make oneself clean, neat, or presentable.
3. To dispose of; settle: cleaned up the unpaid bills.
4. Slang To make a large profit, often in a short period of time: cleaned up during the bull market.
clean house Slang
To eliminate or discard what is undesirable: The scandal forced the company to clean house.
[Middle English clene, from Old English clǣne.]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2020 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:
The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.